Abstract: A transmission line device (200) employs a first ground plane (118) that is disposed on a first dielectric substrate (202). A first conductive layer (210) that encloses a first area (213)is disposed on a second dielectric substrate (206), which substrate is positioned substantially adjacent to the first dielectric substrate (202). A second conductive layer (211) that encloses an area corresponding to the first area (213) is disposed on a third dielectric substrate (207), which substrate is positioned substantially adjacent to the second dielectric substrate (206). A coil structure is thereby provided that can be employed in the fabrication of a transmission line device, according to the invention.

Abstract: In a receiver, a channel quality metric (220) is determined by demodulating a received second stream of discrete data elements (205) using a received first stream of discrete data elements (203) to produce a demodulated second stream of discrete data elements (212). The demodulated second stream is decoded, leading to an estimate of the second stream of discrete data elements (214). The estimate of the second stream is then re-encoded and the resulting re-encoded stream of discrete data elements (216) is compared with the demodulated second stream to produce the channel quality metric. Derived in this manner, the channel quality metric provides a method for detecting decoding errors in a stream of critical data elements.

Abstract: A method of providing operational features for a programmable radio (202) employs a security key (210). The security key (210) is preferably coupled to an interface device (208) and includes at least an indication of a desired feature set. Using this indication, or flashcode (220), the programming system is able to securely program (609) the radio (202) with the desired feature set (504).

Abstract: The present invention encompasses a method of facilitating an audio source change in a digital radio communication system (100). A typical system includes a plurality of audio source units ( 101-103), a plurality of audio destination units (105, 106), and a switching unit (108) for rendering one of the plurality of audio source units (101-103) operable. Upon receipt (302) of an information-bearing frame from an audio source unit, a frame sequence value is identified (304). The expected frame sequence value is then determined (306), and this value is compared to the identified frame sequence value to determine whether or not the received frame sequence value matches the expected frame sequence value. When the frame sequence values match, it is assumed that the frames were sourced from the same audio source unit (i.e., no source change has occurred).

Abstract: A dispatch radio communication system (100) employs a method (200) and apparatus (101) for assigning one of a console station's control modules (113-115) to a communication resource. The assignment is initiated by associating (203) each control module (113-115) with a group of supported resource features and associating (205) each communication resource with a group of employed resource features. The latter association is then used to establish (211 ) a minimum set and an extended set of resource feature requirements for a particular communication resource that is to be added to a console station (109). The former association is used to identify (217) a group of candidate control modules (113-115) at the console station (109) that can support at least the minimum set of resource feature requirements. Upon identification of the candidate group (113-115), the candidate control module (e.g.

Abstract: An electrical circuit (400) includes a first input means (401) for providing an input signal, a first output means (406) for providing an output signal, and a transmission line device (405) electrically positioned between the first input means (401) and the first output means (406). The first transmission line device includes a first ground plane (409) disposed on a first dielectric substrate (402), a first conductive layer (405-1) enclosing a first area on a second dielectric substrate (403) that is positioned substantially adjacent to the first dielectric substrate (402). The transmission line device (405) further includes a second conductive layer (405-2) that encloses an area corresponding to the first area on a first major surface of a third dielectric substrate (404) that is positioned substantially adjacent to the second dielectric substrate.

Abstract: An FM receiver (100) that includes a plurality of filtering elements (120-124) that have various center frequencies and bandwidths that adjust to maximize the signal quality of a desired signal (104) recovers the desired signal (104) by inputting the desired signal (104) to each of the plurality of filtering elements (120-124). Signal recovery is performed on an output of each of the filtering elements (120-124) to obtain a plurality of recovered signals. The recovered signals are then measured to obtain a plurality of signal quality metrics for the desired signal.

Abstract: Determining transmit time of a received signal in a simulcast multi-site communication system begins when a communication unit transmits a message to one or more network receivers. Each receiver transports the received signal with a time stamp to each transceiver in the network via a digital communication network. Each transceiver calculates a wait period, during which, the transceiver may receive the signal and time stamp message from another receiver. Once the wait period expires, each transceiver, using a substantially similar selection method, selects the same received signal to broadcast. Each transceiver then determines a launch time for transmission of the selected received signal, wherein the launch time accommodates the worst case expected transport delay through the digital network.

Abstract: Processing of dispatch calls in a simulcast multi-site communication system begins when a source communication unit transmits a message to one or more network receivers. The received signals are analyzed immediately at the received sites for signal quality. Each of the signals are time stamped to identify when they where received. The received signals are transported with their time stamp and signal quality metric to each of the other sites via a digital communication network connecting the sites. A master transmitter site determines the receiver source with the best quality signal as indicated by the signal quality metric. The master transmitter then transports the chosen best quality signal to each of the other sites via a digital communication network. Each transmitter site performs a transmit operation by storing the chosen best quality signal until it is time to transmit the signal in phase with all the other transmitter sites in a simulcast manner.

Abstract: A method of manufacturing is employed to produce a size-reduced frequency control device (300), according to the present invention. A temperature compensation circuit (304) and an unsealed piezoelectric element (302) are disposed on a substrate (306) such that the compensation circuit and the unsealed piezoelectric element are electrically connected. A hermetic seal (318) is established between a lid (308) and the substrate such that the unsealed piezoelectric element and at least a temperature sensitive portion of the temperature compensation circuit occupy a sealed environment (320). In this manner, dimensions (322, 324) of the frequency control device are reduced.

Abstract: A method is employed by a central controller of a radio communications system, which method provides for sustaining a predetermined level of communication service. The system includes a plurality of voice channels which are allocated among a plurality of subscribers (108-112) using a first control channel (102). In a preferred embodiment, at least one of the voice channels (104, 106) is also control-capable. The method includes evaluating (502) a current loading condition, and comparing (504) this loading condition with an upper loading threshold. Where appropriate, the controller assigns (506) one of the control-capable voice channels as a temporary control channel.

Abstract: A diversity receiver that receives diverse modulated signals may produce a usable signal from the received modulated signals in the following manner. Two modulated signals, each including a desired component and an undesired component, are received by the diversity receiver, wherein each desired component includes an originally transmitted signal and each undesired component includes noise and interference. The diversity receiver estimates each desired and undesired component and produces the usable signal based on the estimated desired components and the estimated undesired components.

Abstract: An electrical circuit assembly (100) includes an electrically actuatable clamping arrangement (108) that provides a reliable, solderess electrical connection between two electrical circuits (104, 106). The present invention is readily adaptable for use with a first electrical circuit (104) that includes at least one electrical contact area (130) disposed on a substrate (102). The electrically actuatable clamping arrangement (108) is then used to provide an electrical connection between the electrical contact area (130) and a second electrical circuit (106).

Abstract: A radio communication system receiver employs a demodulator (104) to recover a received signal. The receiver of the present invention further includes a channel quality estimator (222) for estimating a characteristic of the communication channel over which the signal is received. A first or second decoding technique (220) is selectively employed using the estimated communication channel quality value (223). In this manner, an improved receiver is provided that is able to realize the benefits of either the first or the second decoding technique, depending the channel condition.

Abstract: An electrical circuit (101) that is disposed on a substrate (103) employs a method and apparatus for providing electromagnetic shielding of the electrical circuit (101). One or more compressible, electrically conductive contacts (107), each of which includes a substantially planar portion (201), are coupled at their respective planar portions (201) to a receptacle area (105) on the substrate (103) that substantially encircles the electrical circuit (101). A shielding enclosure (109) having a top portion (110) and a plurality of side portions (111) is positioned upon the compressible, electrically conductive contacts (107) such that the side portions (111) compress at least some of the compressible, electrically conductive contacts (107) to substantially enclose the electrical circuit (101).

Abstract: A modified temperature compensation signal (110) is provided in a temperature compensated crystal oscillator (TCXO) circuit (100) in the following manner. A temperature dependent current generator (104) produces a temperature compensation signal (108) whose amplitude changes responsive to changes in ambient temperature. The temperature compensation signal (108) is scaled, based on a plurality of discrete frequency adjust values (212), to produce the modified temperature compensation signal (110).

Abstract: Data transfer for a time division multiplex (TDM) bus in a communication system that includes a plurality of communication nodes wherein each communication node is allocated at least one time slot of the TDM bus can utilize the following protocol to improve flexibility. When a communication node has an information packet to transmit, it must determine whether it is changing from a first information packet type to a second information packet type message. If a change from transmitting a first information packet type to transmitting a second information packet type is determined, an information type transition message is transmitted via the allocated time slot during a first frame cycle. Upon receiving the information type transition message, at least one other communication node stores the information type transition message.

Abstract: An electrical circuit (500) includes an input means (503) for providing an input signal, an output means for providing an output signal, and a transmission line device (421) disposed substantially between the input means (503) and the output means. The transmission line device inludes a first ground plane (505) disposed on a first dielectric substrate (502), and a first conductive layer (421-1) disposed, and enclosing a first area, on a second dielectric substrate (506) that is positioned substantially adjacent to the first dielectric substrate (502). The transmission line device (421) further includes a second conductive layer (421-2) that encloses an area corresponding to the first area on a first major surface of a third dielectric substrate (504) that is positioned substantially adjacent to the second dielectric substrate (506).